Code groups: assessing regional litter survey results. Support text for presentation

Methods

  1. data collection
  2. scope

Summary data

All surveys

  1. all data
  2. project lakes

Code groups

  1. summary data
  2. components
  3. survey results
  4. monthly median and change
  5. key values by lake

Code groups: Significant events

  1. definition
  2. significant events per lake
  3. frequency of ocurrence per group and lake

Regional assessment tools

Find the locations on one lake that may be hotspots for litter accumulation. Identify the ones that may be interesting to monitor in the future. Use the provided graphic and map to make your decision.

Using non aggregated data

Methods

Data source, time frame, geographic scope and collection methods 

The data for this analysis is the results from beach-litter surveys conducted in Switzerland.

All surveys that were conducted on Bielersee, Neuenburgersee, Thunersee, Walensee, Zurichsee, Lac Léman, Brienzersee and Lago Magiore were considered.

The data was collected according to the protocol described here https://www.plagespropres.ch/. In brief all visible data is collected along a beach within a measured distance from the waters edge. The width of the survey area depends on the terrain and the water level. The visible strand line or the nearest physical structure defines the width of a survey (figure 1).

Surveys were conducted by the following organizations:

1. hammerdirt
2. Association pour le Sauvegarde du leman
3. Solid Waste Management Ecole Polytechnique Federal
4. Ecole International de Geneve
5. Precious plastic leman
6. Why isn't your association here?

This analysis is an open source document. The working note book is available in the repository located here https://github.com/hammerdirt-analyst/iqals.

Scope of surveys

The scope of the surveys includes all accessible shoreline on the previously mentioned lakes given the following conditions:


1. Public transport is 1/2 hour away on foot
2. The land is open to the public
3. The location is safe
4. There is no reason to not do the survey

Summary data: all surveys

Since april 14, 2020 301 samples have been recorded, 266 from lakes and 35 from rivers (figure 1, table 1).

The number of samples exceeds both our personal expectations and the contract requirements. However there are still three more months of sampling.

Thanks to the following individuals for their participation:

1. Helen Kurukulasuriya
2. Martin Brenvasser
3. Adrien Bonny
4. Debora Camaro
5. Geatan Busser
6. Marie-France Labelle
7. Andreas Gauer
8. Gaetan Buser

Most common objects: all surveys

Project lakes summary data 

There are eight project lakes:


1. Zurichsee
2. Lago Maggiore
3. Thunersee
4. Lac Léman
5. Bielersee
6. Neuenburgersee
7. Walensee
8. Brienzersee


Brienzersee was added to the surveys beacuase of it's position in the catchment area of the Aare (figure 2, table 3).
3

Most common objects: project lakes

Project lakes: objects grouped by use or physical characteristics

Group components

Survey results per code group

Median monthly survey results

Key values per code group

Project lakes: significant events by code group and lake

Definition of significant event: a significant event is defined as a survey result that exceeds the 90th percentile of all surveys for that code group. In this report the 90th percentile is considered for all surveys in the project lakes.

Figures and data produced by this notebook:

Hopefully that just worked for you

if not contact analyst@hammerdirt.ch